# Offer calculator > Model the ROI of a discount or promotion — first-order profit, payback period, and projected lifetime value — then save it as a reusable scenario. Source: https://help.tryordinary.com/features/offer-calculator --- Planning a discount or promotion? The **ROI & Offer Calculator** shows whether the math works — what you make (or lose) on the first order, how long until a customer pays back their acquisition cost, and what they're worth over time. Open the dedicated **Offer Calculator** from the main navigation and pick a product from the search at the top, or launch it for a specific product from the **Offer** button on any row of the Products page. ## Offer inputs The left panel is where you model the offer — drag a slider or type a value: - **Offer price** — the price you're testing (pre-filled from the product). - **Discount** — the markdown you're considering, as a percentage. - **CAC** — what you spend to acquire a new customer. - **Product cost** — your cost of goods for one unit. - **Shipping cost** — what it costs you to ship one order. - **Gross margin** — calculated for you from price and costs, shown as a gauge. - **Repeat frequency** — how many orders a customer places per year. Seeded from your store's retention behavior, and fully editable. **Advanced options** holds the rest: forecast horizon (months), payback target (months), free-shipping handling, sales channel, and any extra per-order costs (pick fees, royalties, and so on). ### Auto-filled from your store Two inputs pre-populate from your Shopify data so you don't retype them: - **Product cost** — from the variant's "Cost per item" field in Shopify admin, if you've set it. - **Shipping cost** — a representative rate from your default Shopify shipping profile, or the median of recent orders' shipping amounts as a fallback. Both are always editable — auto-fill only seeds an empty field, and anything you type sticks. ## What it computes The middle **Offer Summary** and the bottom metric strip translate your inputs into the numbers that matter, using your store's actual retention curve from the last 365 days (see [Cohort retention analysis](https://help.tryordinary.com/features/cohort-retention)): - **Average order value** — the price after the discount. - **Contribution margin / order** — what's left after product and shipping costs. - **Net profit / order** — contribution margin minus CAC (the first-order picture). - **Payback period** — how many months until a customer's repeat orders cover their CAC. - **Projected profit** — expected profit per customer over your forecast horizon. - **Projected CLV** — expected lifetime value per acquired customer. - **LTV:CAC** — lifetime value relative to acquisition cost, a quick health ratio. - **Margin impact** — how much the discount moves your per-order margin. - **Risk level** — a fast read on whether the unit economics are healthy. The **forecast chart** on the right plots cumulative profit and expected CLV per customer across their first orders, with your store's retention curve overlaid. Toggle the cohort between **Same product** (repeat purchases of this SKU) and **Any repeat** (repeat purchases of any product) to see how each assumption changes lifetime value. ## Scenarios Found an offer worth keeping? Click **Save Scenario**, give it a name (for example "Summer Promo – 20% Off"), and it's saved for your whole team. Reopen it any time from the **Scenario** dropdown to reload every input, or compare a few approaches by switching between them. Saving with a name that already exists updates that scenario. > **Create Campaign** (coming soon) will let you carry a modeled offer > straight into a live campaign. ## How to interpret the output - **Low risk / strong LTV:CAC** — the promo pays back within your store's typical retention window. Ship it. - **Medium risk** — tight margins or slow payback. Run it as a deliberate customer-acquisition play you're willing to absorb. - **High risk** — the offer never recovers CAC. Dial the discount back, improve retention (the underlying product problem), or rethink the offer. ## What it doesn't model - Cannibalization — promoted customers might have bought anyway at full price. - Brand/equity effects — discounting too often trains customers to wait for sales. - Competitor response — a deep discount on a low-differentiation product might trigger a race to the bottom. Use the calculator for the math floor. The qualitative judgment is still yours. ## Tips - **Run the numbers at multiple discount depths** (10%, 20%, 30%). The payback period usually bends non-linearly; sometimes 15% is dramatically better than 20% because cost of goods eats the margin. - **Check different products.** High-margin hero SKUs tolerate deeper discounts than low-margin consumables. - **Save the variants you like as scenarios** so you can revisit them after a promotion and check whether the retention math still holds. ## Related features - [Cohort retention analysis](https://help.tryordinary.com/features/cohort-retention) — the retention data the calculator reads from. - [Customer lifecycle stages](https://help.tryordinary.com/features/customer-lifecycle) — a complementary view of "who comes back." - [Products — catalog and performance](https://help.tryordinary.com/features/products).